My navigation system on my 2016 Prius has stopped working. When I turn on the car, the map will usually come on screen for a couple of seconds, then the following message is displayed: Unable to read the map SD Data. Check the map SD. If necessary, consult your dealer. It had been doing this on and off for a number of months but would usually come back on when I restarted the car and stay on. Now the map is gone completely. I've removed the SD card, cleaned the contacts, and reinserted it. Doesn't make any difference. I think I bought the SD card in 2020 and it had a 2019 map. My question is, does this error look like it's just a problem with the SD card that an updated map would fix, or could it be a problem with the card reader? Thanks for any insights/experiences with this problem.